1. Field of the Invention
The invention relates to a monitoring process on machine assemblies of rotary printing presses with central lubrication, with such machine assemblies being, for example, printing units. Such machine assemblies have a multiplicity of bearing points, engaging teeth, crank drives and similar structures, which, during operation, are supplied with the necessary quantity of lubricating oil in accordance with a specific lubrication schedule. Owing to the supply of oil to the individual lubrication points, often at pinpoint locations, only a relatively small quantity of lubrication oil is needed.
2. Description of the Prior Art
Normally, the supply of lubricant is usually slightly greater than the demand, which may possibly only be in the order of a few drops of lubricating oil. The demand will depend on the particular requirement of the lubrication point, such as a bearing. This slight oversupply of oil drips or flows away from the individual lubrication points and is collected in oil channels or other oil-collection reservoirs. Since, however, in certain machine assemblies in rotary printing presses, e.g. in printing units, there may be a system for the cooling of rollers in the associated inking unit. Therefore, the possibility cannot be discounted that leakage losses of the coolant from supply lines occur. If water is used as a coolant, the possibility cannot safely be ruled out that, for example, at a rotary connector for the supply of coolant, a few drops of water may escape after the machine has been in operation for some period of time. Unless the water is able to evaporate, these drops often may enter the lubrication oil as it flows or drips away from the mechanisms being lubricated and are collected together with the lubrication oil. There, then, is the danger that, when the collected oil flows from oil collection reservoirs into the supply tank of the central lubrication system, the drops of water will also flow to a lubrication point. In such a case, the machine part that is to be lubricated may be damaged during machine operation by the water that has been supplied to it via the lubricating system. Conventionally, the only reliable method of preventing contamination of the lubricating oil has been either to clean the collected oil or to totally remove the collected oil. The cleaning of the oil, or the discarding thereof, often represents a considerable cost factor for the operation of a rotary printing press.